Question

A student places a strip of solid magnesium metal into a beaker full of $100.mL$ of $3.0$ M hydrochloric acid solution. The student observes bubbling and the disappearance of the magnesium metal.
Which species is being oxidized and which species is being reduced in this reaction?

• A. Magnesium being oxidized and the chloride ion is being reduced.
• B. Magnesium being oxidized and the hydrogen ion is being reduced.
• C. Magnesium being reduced and the chloride ion is being oxidized.
• D. Magnesium being reduced and the hydrogen ion is being oxidized.

Answer 1

The correct option is A Magnesium being oxidized and the chloride ion is being reduced.

The reaction here is, $Mg\left(s\right)+2HCl\left(aq\right)⟶MgC{l}_2\left(aq\right)+H_2\left(q\right)\uparrow \downarrow \downarrow \downarrow \downarrow 0H⟶+1Mg⟶+2H⟶0Cl⟶-1Cl⟶-1$

$Mg$ is oxidised from $0$ to $+2$.

$H$ is reduced from $+1$ to $0$.

$MgC{l}_{2}x+2(-1)=0x=+2$